Piston pile driver



J. WOHLMEYER PISTON PILE DRIVER Jan. 19, 1937.

,. Filed May 2, 1934 l Eq #Sdi Jg v Patented Jan. 19, 1937 PISTON PILE DRIVER VJosef Wohlmeyer, Vienna, Austria Application May 2, 1934, Serial No. 723,592. In Hungary and Germany August 16, 1933 11 Claims.

vThis invention relates to an improved method of and appropriate means for driving piles and the like. The hitherto known pile-drivers in which the tup is moved in both directions by means of a gaseous medium under pressure (air, steam, or the like) necessitate the use of a heavy casing. The casing'is made so heavy that the reaction pressure of the driving medium acting in an upward vdirection on the delivery of the blow is not capable of eiecting any appreciable jumping of the parts of the driver not pertaining tothe. tup, i. e. the non-impelled parts of the apparatus, which parts are herein to be understood'as comprised under the term casing.

The present invention provides a piling-driving method and apparatus which permits of the casing being made `of verylight weight, and which consequently reduces the'total weight of the plant to a great i extent' as compared with hitherto known Atypes of construction. This result is achieved by the arrangement that the casing of the pile-'driver is resiliently connected to the pile or other object to be driven, so that at first the weight of the pile, and later on the increasing adhesion ofthe pile in the ground, are utilized rfor the absorption of the upwardly acting forces 'of reaction. l

This principle is incompatible. with the rigid :connection of the pile tothe casing ofthe driver,

as yalready proposed for other purposes, since the intermittent movements of the pile produced by 'the blows delivered by the driver would be transmitted to the casing, with the result that the casing would become damaged and the conne-ction loosened or disengaged. The resilient yielding connection provided in accordance with the present invention obviates these drawbacks.

A furtherV feature of the invention consists in the automatic arresting of the percussion action on the occurrence of slackening or disengaging of the connection between the casing and the pile.

VForms of construction embodying the invention are shown, by. way of example, in the accompanying drawing, in which:

Figsgl,y 2, and 3 show the percussion head of a pile-driver or -drawer in which the cylinder serves `as the tup.

Figs. 4, 5, and 6 showk the percussion head of a pile-driver or pile-drawer in which a piston isl constructed toserve as the tup.

In the form of construction shown in Fig. 1 the with the interposition of springs 8. 'Ihe connectlng of the casing to the pile can also be eiected in any other known manner, for instance by means of gripping jaws, clamp rings, chains, and Athe like. The closing of tl'e connecting grip or fastening on the pile can be effected either by hand, with the aid of screws and the like, or by means of the gaseous pressure medium used in the operation of the pile-driver itself.V The cylinder and piston constituting the actuating means proper can also be used in place of the resilient interposed means (springs or the like) mentioned above.'

With the construction shown in Fig. 1, in which the cylinder I of the percussion head serves as the tup of the pile-driver, in order to prevent this cylinder from delivering injurious idle blows or blows upon the piston 2, in the event of the percussion head casing becoming disconnected from or but loosely connected to the pile, an automatic stopping device is provided in accordance with the invention `as mentioned above, by which the rigid system comprising piston rod 3, piston 2, and controlling head 4 is shaped at its upper end in the form of a piston 5 which is provided with` peripheral slotsy or -apertures 6 for the admission of the compressed driving medium, and which ts and travels tightly in the upper portion 9 of' the'casing. The inlet slots 6 are arranged at such a level that they are covered over by the cylink drical wall of the upper portion 9 of the casing ywhen the piston 5 is in its lowest position. When the percussion head casing I is firmly connected up to the pile I9, the descent of the piston system 5, 4, 3, 2 is prevented by the. pile I 9 against which it bears. As soon, however, as this connection becomes slack or disengaged the driving medium in the upper portion 9 of the casing will press the piston 5 into its lowest position, with the result rthat the admission of driving medium to the control head 4 is interrupted, and the driver is stopped. For effecting the relative displacement between the tup member bearing uponY the upper end of the pile and the casing to be attached to the pile spring force can also be employed instead of the force of the driving medium. In this case, and also in the case of the previously described form of construction, the interruption of the supply of the driving medium can be effected by means of a closure member actuated by the above-mentioned relative movement.

This arrangement can be employed in connection with any type of' double acting hammer with percussion cylinder, including the normal type of pile-'driver with heavy casing adapted merely to ,of a percussion hammer.

be placed in position upon the upper end of the pile. In the latter case the arresting action will occur as soon as the tup does not bear with its full weight upon the pile.

If the ramming device with percussion cylinder be employed as a pile-drawer, with the utilization of the percussion effect of the ascending tup against a cross-bar, the arresting device according to the invention can be used for the automatic stopping of the plant as soon as the static tension under which the pile-drawer must be retained falls below the prescribed limit.

In the arrangement shown in Fig. 3 the static tenson is applied at the upper eyelet 'I tothe piston system 5, 4, 3, 2. The cylinder strikes against a cross-head I I which embraces the piston rod, and f which is provided at each end `with a dependentr traction link I2. 'I'he lower ends of the latter are connected to a cross-bar I3 to which there is ar-v, ticulated a suitable gripper I for the grasping" .of the various types of piles used. In accordance with the invention the two traction links terminate at the upper end in two spindles I4 adapted to pull against springs 8 which bear against the upper portion 9 of the casing. When the gripper I5 has once been connected up to the. pile, and a Asteady tension applied to the uppereyelet 'I which is equal to or greater than the pressure of the driving medium on the portion 5 of the piston system, then the latter will ascend as far as possible relatively to the upper portion 9 of the percussion head casing, thereby disclosing the inlet apertures 6, so that the pile-drawer can begin to strike.

`As soon, however, as the steady tension in an upward direction diminishes, in consequence of the extraction of the pile from the'ground, weakening of the pull at the winch, or for any other reason, to such an extent that it becomes less than the pressureY of the driving medium on the piston 5 it will be clear that the latter will descend to its lowest position relative to the upper portion V9 of, the percussion head casing, and thereby in terrupt the supply of the driving medium Auntil the required tractive force is resumed.

, Similar arrangements can also be employed in connection with rammers of all kinds in which the tup is in the form of a percussion piston (see Figs. 4, 5, and 6) Fig. 4 shows a device of this nature in the form In this case the light weight cylinder casing I6 is attached to the pile I9 rigidly or with the interposition of springs I1. The anvil I8 takes the form of an off-set piston against the annular collar surface of which the driving medium is brought to bear. In the lhighest position of the anvil relatively to the casing I6 the driving medium is admitted to the control port manifold 20, since the neck 2| of the anvil exposes the slots or ports 22. Assoon, however, as the tension of the springs I'I becomes less than the pressure of the driving medium uponA the `annular collar surface of the anvil this latter moves outwards relatively to the casing I6 and thereby covers the slots 22, with the result that the admission of the driving medium is interrupted untiltherequired tension is restored.

'I'he same arrangement can also be employed with the usual vrammers with heavy casing which 2 is suspended in the reverse position for use as a pile-drawer. In this case the anvil 23 acts upon the traction links 24 either directly, as shown in the drawing, or through the intermediary of a cross-head. As soon as the steady pull on the eyelet 25 becomes less than the pressure of the driving medium on the annular collar surface of the anvil, the latter ascends relatively to the casingand the slots 22 are covered over, with the result that the pile-drawer is arrested until the necessary tension is restored. As in the case of ramming, the stopping of the plant when serving as a pile-drawer can likewise be effected indirectly and also by spring action.

Finally, in accordance with the invention the pressure of the arresting piston is also made use :of to effect the gripping of the pile by bringing about the closing movement of a clamping or gripping appliance.

Fig. 2 shows a form of construction in which the twowedge-shaped jaws30, which grasp the pile I9, are arranged to slide on two oblique surfaces 3| on the gripper arms 29. These arms `can be set to suit the diameter of the pile by .means of thetwo tension screws 32, the cheeks being maintained in the uppermost position by means oizsprings. The admission of the driving medium to the percussion head 9 causes the piston system 5, 4, 3, 2 to be depressed whereby the -two jaws Y3|) are caused to grip the pile I9 with ,vious frictional closure against the pile.

Fig. 5 shows an analogous arrangement for use with rammers having a percussion piston. In this case. the pressure of the anvil I8 acts upon two wedge-shaped jaws 33 which coact with oblique surfaces 35 provided on the gripper arms 34.

I claim:

1 .Apparatus of the character described comprising a percussion rammer having a tup portion adaptedgto bear against the object to be rammed, a casing portion, means for connecting the casing portion resiliently to the said object, means for supplying a driving medium to the rammer and means associated with the said portions for interrupting the supply of driving me'- dium to the said rammer automatically on the occurrence of loosening of the said connecting means.

2. Apparatus as claimed in claim 1 in which the said automatic interrupting means comprise through passages and a closure member adapted to close off the said passages on the occurrence of relative movemen't between the said tup portion and casing portion in response to the pressure of the said driving medium. 1

3. Apparatus as claimed in claim 1 in which the'said automatic interrupting means comprise through passages, a closure member adapted to close off the said passages, and spring actuating means, the said closure member being adapted to become operative on the occurrence of relative movement between the said tup portion and casingfp'ortion in response to the pressure of the said spring actuating means.

4. Apparatus as claimed in claim 1, when employed for pile-drawing the said automatic interrupting means being adapted to act in response to the reduction of the tractive force applied from the outside to the rammer below a predetermined limit.

5. Apparatus as claimed in claim 1 in which the said rammer includes a rigid system composed of a piston, a piston rod, and a control head, the tup portion being in the form of a cylinder, the upper end of the rigid system being shaped to form a piston having apertures at its periphery for the admission of a. driving medium, and adapte-d to move with accurate fit in the upper part of the said casing portion, so that when the said piston is in its lowest position the said apertures are closed by the inner surface of the said upper part.

6. Apparatus as claimed in claim 1 in which the said tup portion is in the form of a piston, and further comprising an anvil in the form of a piston of off-set reduced diameter, and adapted to admit the said supply of driving medium when the said casing portion is in its lowermost position and to interrupt the same when the said casing portion becomes moved away from the said anvil, the saiddriving medium having the tendency to retain the said anvil in the position of closure, whereas during the working of the rammer the weight of the said casing portion together with the inherent weight and adhesion to the ground of the object rammed tend to retain the said anvil in the position of admission.

7. Apparatus as claimed in claim 1, when employed for pile-drawing, and in which the said tup portion consists of a percussion cylinder, characterized by the fact that traction links coupled to the pile are adapted to act upon springs bearing against the upper part of the said casing portion, while the tensile force required for the pulling of the pile-drawer is applied to a rigid system comprising piston, piston rod, and control head, through the intermediary of a rod traversing the said upper part.

8. Apparatus as claimed in claim 1 when employed for pile-drawing and in which the said tup portion is in the form of a piston, characterized by the fact that traction links are articulated to an anvil in the form of a piston of offset reduced diameter, while the tensile force necessary for the straining of the pile-drawer is applied to the said casing portion and brings this latter, when the said tensile force exceeds a predetermined limit, against the pressure of the driving medium acting upon the said anvil, into its upper most position in which the inlet passages for the driving medium are disclosed.

9. Apparatus as claimed in claim 1, characterized by the fact that the pressure of the said tup portion bearing upon the object to be rammed eiects the closing gripping movement of the connecting means upon the said object.

l0. Apparatus as claimed in claim 1, characterized by the fact that the pressure of an arresting piston effects the closing gripping movement of the connecting means upon the said object.

11. Apparatus as claimed in claim 1, characterized by the fact that the pressure of an arresting piston acts upon two wedge-shaped jaws adapted to coact with converging inclined surfaces on gripper arms.

JOSEF WOHLMEYER. 

